AGRICULTURAL CHEMISTRY - EVALUATION OF AN AGRICULTURAL SCIENCE IN PRESENCE AND FUTURE

Agricultural chemistry is the science dealing with the interactions between the yields of plants and factors affecting growth. It aims to improve the quantitative and qualitative yield by means of determining the supply of the needed growth factors. Agricultural chemistry, like medicine, is both applied and fundamental science. Agricultural chemistry is divided in two parts: science of plant nutrition and science of fertilization. Liebig defined Agricultural chemistry in the 19th century in terms of plant nutrition and fertilization. Industrial production of fertilizer was the dominant concern until the middle of the 20th century. The environmental consequences of the agriculture were not considered. Environmental problems became more serious in the 1950's with the increasing use of combine harvesters. This increased the amount of liquid manure. Stable manure containing straw has several environmental advantages compared with slurry. Increasingly toxic industrial materials were occurred in wastes. The use of these wastes for plant production became more and more questionable. The application of nutrients corresponding with demand conflicts with the use of the soil as a means of disposal of wastes from animals kept at high population densities. Therefore, the task of agricultural chemistry must be to study the control of nutrient release from organic fertilization. It is against all understanding to apply fertilizer in accordance on loading limits of soils. A further field of problem is the contamination (e.g. phosphorus and nitrogen) of surface water and ground water, caused by agriculture, industry and traffic. This contamination of rivers, lakes and the oceans from agriculture is a loss to the community as a whole. The household consumption of drinking water is 150 1/ person/day, but the human requirement is only 2-3 1. The high raising of ground water leads to a strong undertow, which causes the washing out of soluble mineral elements, especially nitrogen. Agricultural chemistry has also to consider the output of the nutrients and the possibility of recycling. This requires the calculation of balances. Mineral fertilizers are nutrients whose application rate and timing may be better calculated far organic fertilizer. The value of organic fertilizer can only be calculated, if its content of nutrient elements is known. The combination mineral and organic fertilizer leads to the optimum humus and nutrient supply for plant production. The conservation of the definition agricultural chemistry is a moral obligation. Agricultural chemistry is now in a second area. The aim is not to fight against hunger, rather to secure the supply of plant nutrients from nutrient fluxes. It is now time to come out of the darkness which false policy lead agriculture and agricultural chemistry into. It is the task of both organic and conventional agriculture to preserve the resources of soil and plant as a resource for cultivating land in the European tradition.